Draft proofing doors

[fenhayman]

My workshop is in a conventional garage attached to the house. Access is via an internal door and the usual pair of doors at the front.
The large doors are sound but are gappy and draughty.
I'm thinking of a heavy curtain on the inside but don't know what material to use. Have a good pole for them to hang on. I don't want to re-hang or re-fit the doors.

 

[DBT85]

I have foam strip betwixt door and frame, and have a garage seal thing to put along bottom, though I just have double doors, not an actual garage door.

It shouldn't be too hard to actually eliminate the draught rather than just mitigate it with a curtain.